It's all well and good hailing how safe designs are, but none of the designs have safety features designed around somebody intentionally trying to blow up the reactor, they're all designed around accidents happening, accidents that generally don't involve explosives, the reactors are built to endure some abuse, but if somebody wants to blow one up, there's very little stopping them
... , if the reactors are intentionally blown up at Zaporizhzhia it'll be Chernobyl 2.0...
Nuclear plant design does take intentional sabotage into account to a certain extent - there are access control systems inside the plants controlling access to sensitive areas with background checks for all staff, things brought in and out are checked, men with guns guard the sites, there are big fences round the outside etc. Automatic safety systems and warnings along with the inherent design of modern plants would make it difficult for a sabatour that did manage to get access to a sensitive area to endanger the plant. Scaling it up further they are also designed to withstand jet aircraft being flown into them, and a lot of the most critical parts would be resistant to small explosions purely because they of how physically strong they are, with redundancy built in if one part is damaged etc.
In some ways you're right though, because with enough effort humans can destroy pretty much anything. If you planted enough explosives around the reactor you could recreate a Chernobyl type event - the big Chernobyl explosion was apparently guesstimated to be about 300 tons of TNT equivalent, so Russia could possibly carry in 10 truckloads of TNT and create a similar effect and I imagine that much TNT would make the containment building worthless (although the core of an RBMK reactor (chernobyl) is a lot more massive, and has more than twice as much fuel in it, so there would physically be a lot less material to spread around from a reactor at zaphorizhzhia, for example). The contamination would still be nowhere near as bad as chernobyl due to the mechanism though.
You can't really design anything to withstand that sort of malicious action though. Dams, motorway junctions, boats, tall buildings, gas supply systems, bridges, tunnels etc are all vulnerable to organised sabotage. All of them could cause significant civilian suffering if you blew them up.
4000 - 27000 seems to be the estimated death toll from chernobyl, including long term cancer deaths etc. Just to keep a sense of scale, far more than that have already died in Russia's invasion of Ukraine. Russia is quite capable of causing massive suffering without needing to use nuclear power plants.
If they want to cause death and misery in that way then they can, but it isn't really a problem with nuclear power, especially modern nuclear power plants. Its a problem with a terrorist state.